Device for a multi-feed circular knitting machine

ABSTRACT

A device for a multi-feed circular knitting machine, which permits the carrying out of fancy operations repeated at each feed with the aid of a single assembly of movable cams in connection with only one of said feeds. The device comprises jacks raised and lowered by common selection cams and lower jacks raised by cooperation with said jacks. The lower jacks have at their lower end a foot cooperating with a control ledge arranged on the needle cylinder in order to cause the lower jacks to project with a butt opposite to the foot and to engage with cam means provided for carrying out the fancy operation on the fabric.

Tenconi United States Patent DEVICE FOR A MULTI-FEED CIRCULAR KNITTING MACHINE [72] Inventor: Riccardo Tenconi, Via della Tallera 19, Varese, Italy [22] Filed: June 11, 1970 [21] Appl. No.: 45,334

[52] US. Cl ..66/42, 66/49, 66/50 R [51] Int. Cl. ..D04b 9/18 [58] Field of Search ..66/42, 49, 50 R, 50 B, 25, 66/75 [56] References Cited UNITED STATES PATENTS 2,193,872 3/1940 Jackson et al ..66/50 B 2,987,898 6/1961 Ferraguti ..66/50 B X 1,947,558 2/1934 Lombardi ..66/50 B 3 ,181 ,940 5/1965 Tenconi ..66/49 3,097,510 7/1963 Brown ..66/50 B 3,184,929 5/1965 Reymes-Cole ..66/50 R 2,143,832 1/1939 Leedham ..66/50 B 2,627,736 2/1953 Lawson ..66/42 FOREIGN PATENTS OR APPLICATIONS 521,264 5/ 1940 Great Britain ..66/50 B 351,046 6/1931 Great Britain ..66/50 R 641,866 7/1962 Italy ..66/50 R Primary ExaminerWm. Carter Reynolds Att0rneyGuido Modiano and Albert Josif [57 ABSTRACT A device for a multi-feed circular knitting machine, which permits the carrying out of fancy operations repeated at each feed with the aid of a single assembly of movable cams in connection with only one of said feeds. The device comprises jacks raised and lowered by common selection cams and lower jacks raised by cooperation with said jacks. The lower jacks have at their lower end a foot cooperating with a control ledge arranged on the needle cylinder in order to cause the lower jacks to project with a butt opposite to the foot and to engage with cam means provided for carrying out the fancy operation on the fabric.

2 Claims, 4 Drawing Figures PATENTED SEP 12 m2 SHEET 1 0F 4 INVENTOR RICCARDO TENCONI PATENTEDsEP 12 I972 3.690.125

sum 2 0r 4 INVENTOR IICCARDU TENCONI BY WM AGEN T PATENTE D 2 I 2 3.690.125

sumunm INVENTOR ifICCAi-QDO TEHCONI AMI HI DEVICE FOR A MULTI-FEED CIRCUIIAR KNITTING MACHINE BACKGROUND OF THE INVENTION A The present invention relates to a device for a multifeed circular knitting or stocking machine which permits the carrying out of fancy operations repeated at each feed with the aid of a single assembly of movable cams in connection with only one of said feeds.

It is known that in multi-feed circular knitting machines for stockings of the type utilizing needles controlled by underlying pushers or jacks which move vertically in corresponding slots in the needle cylinder, and used for knitting, movable cams are provided at each of the feeds, supported by the machine casing, and which can be controlled selectively in order to obtain the desired knitting effects. The purpose of these movable cams is thus to be brought into a working position according to a predetermined sequence, so as to engage the butts of the jacks, thus moving them upwards and downwards. Bymeans of this controls the required needle trajectory is obtained during the rota tion of the cylinder, in such a manner as to retain in a row of knitting one or more stitches of the previous row, or to discard a certain stitch inside a row of knitting, or further to make a loop with a thread brought from a suitable thread guide in addition to the main thread.

All these operations necessarily presuppose that the movable selection members (and mainly the cams mentioned above) form groups which are repeated at each of the feeds. Thus for example, for a four feed machine four complete practically identical series of movable cams are provided along the development of the casing, which are put into the operating position one after the other.

It can be understood that such an arrangement and cams are provided only at the first feed, and comprising lower jacks provided with butts, which move in the slots of the needle cylinder under the jacks, connected to said jacks in such a manner as to be able to slide upwards in said slots, entrained over a first section by said jacks and thrusting said jacks over a second section successive to the first; a guide track for the lower jacks at least in a position corresponding to the successive feeds of the machine substantially reproducing the trajectory which is described by the needles at the first feed; thrust means acting on said lower jacks so as to make them project their butts towards the outside of the respective slot and making them engage with said 5 track; said lower jacks being guided by said track so d I l d t Structure Is very complex an thus aso elcae 40 acks(illustratedrespectivelym FIGS.3a,3band3c);

because the possibility of faults or jamming due to bad operation of the movable cams is high because of the number of feeds of the machine.

SUMMARY OF THE INVENTION An object of the present invention is to obviate these disadvantages by providing a device which eliminates the necessity of disposing the same number of movable cam assemblies as the number of feeds of the machine, by the use of a single series of movable cams at one of the feeds of the machine. The repetition of the fancy operation at the other feeds of the machine is no longer entrusted to cam assemblies (with their corresponding control members) of the movable type similar to the former, but to fixed guide tracks, which are interchangeable each time that a certain type of knitting is to be carried out instead of another.

In this manner the number of movable members of the machine is substantially reduced, its structure is simplified, its cost is lowered, and the cause of a large number of operational anomalies and irregularities is removed. According to the invention there is provided a device for a multi-feed circular knitting machine of the type comprising a rotatable needle cylinder provided along its generating lines with slots in which needles and jacks move vertically, provided with butts for engaging movable cams for the selection and control of the movements of the needles, in which said movable that they move vertically in the respective slots, so thrusting the jacks and causing the needle trajectory already made at the first feed to be repeated at the successive feeds of the machine.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages will be evident from the detailed description of a preferred embodiment of a device according to the invention, illustrated by way of example in the accompanying drawings in which:

FIG. 1 is a vertical sectional view of the cylinder and the members related to it, of a circular knitting machine incorporating the device according to the invention;

FIG. 2 is a diagrammatic and indicative view of the development of the locks with the cams acting on the needles, jacks and lower jacks respectively, in positions corresponding with two successive feeds of the machine (only one of which is provided with the conventional system of selection cams);

FIG. 3 shows a detail of FIG. 2 in relation to three successive positions assumed by the jacks and lower FIG. 4 is a diagrammatic plan view of the arrangement of a thrust cam working in combination with the lower jack track.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows diagrammatically the multi-feed knitting machine utilizing the device according to the invention. The figure shows the fixed frame 1 of the machine, in which the needle cylinder 2 is rotatably supported, fitted on to a tube 3 which is rigid with a crown gear 4 engaged with a gear wheel 5 which receives the required rotary movement from a motor (not illustrated) by way of the shaft 6.

In longitudinal slots 7 of the needle cylinder 2, needles 8 are arranged and below them the jacks 9 controlled so that they cause the needles 8 to move up and down in the respective slots. The cylinder 2 upperly carries a ring 10 provided with radial slots in which the sinkers ll slide controlled by fixed cams arranged in the cover 12. The parts briefly described in the foregoing description are well known and common to circular knitting machines for the manufacture of stockings.

Passing now to a more detailed description of the characteristic members of the device according to the invention, it should be observed that below the jacks 9 there are lower jacks 13. Consequently in each slot of the needle cylinder 2 there are, from top to bottom, a needle 8, ajack 9 and a lowerjack 13.

The jacks 9, below the zone provided with the butts 9a, have actuation means for dragging or urging the lower jacks 13, which comprise a lower appendix 14 which defines at its lower extremity a hooking tooth 15 with which a counter tooth 16 of the lower jack 13 cooperates. The appendix 14 is spaced from the bottom wall of the slot 7, so forming a space 17 inside which the extremity 16 of the lower jacks 13 can slide. The section of the jack 9 which defines the space 17 has a pushing edge indicated by the reference numeral 18.

The lower jack 13 has a characteristic tapered shape, determined by the fact that the longitudinal edges of the lower jacks are slightly convergent downwards. Close to their lower extremity the lower jacks 13 are provided with a butt l9 dimensioned in such a manner as not to project from the slot 7 when the lower jack l3 lies with its longitudinal back 13a against the bottom of the slot 7 (FIGS. 3a and 3b). The lower jack 13 comprises at its lower extremity a foot 20 turned towards the inside of the cylinder 2 and defining an inclined surface projecting into the slots 7. Said cylinder is provided lowerly with an annular ledge 21 having an outer peripheral surface with a diameter equal to that of the needle cylinder 2 inside the slots (FIG. 1). The positions and dimensions of the foot 20 and the ledge 21 are such that when the lower jack 13 is made to rise, and the foot 20 engages with the annular ledge 21, the lower jack 13 moves slightly towards the outside of the slot, so that the butt 19 is made to project from the slot (FIG.

As stated, the circular machine utilizing the device according to the invention is of the multi-feed type.

Suppose for example that it is of the four feed type. One of these is chosen as first feed" while the others may be defined conventionally as successive feeds."

The machine controls in a conventional manner the fixed cams 23 for the needles and the movable earns 24, the fixed cams 25 for the jacks and movable cams 26 which move the butts of the jacks 9, which move the needles to tuck height such that the tongues of the needles do not become unloaded (i.e., to a basic height above which the operation takes place). As can be seen, all the cams mentioned in the foregoing description have an arrangement which is repeated periodically for each of the feeds.

Further, at only the first feed, selection earns 27 are provided for the selection of the stitches and the consequent fancy knitting operation.

The selection cams 27, which engage the butts of the jacks 9, are not present at the successive feeds.

At the height of the lowerjacks 13 a track 28 is provided in a cam member which, engaging the butts 19 of the lower jacks, controls its rise and fall movements. The shape of the track 28 of the cam member is characteristic. It comprises a first slightly sinuous but practically flat zone A which extends on the casing, covering an arc of width corresponding to the zone of influence of the first feed. Beyond zone A, the track 28 has a shape (zone B) which practically reproduces the trajectory imposed on the needles 8 by the selection cams 27, this trajectory being determined by the fancy work on the knitting at the first feed. The shape B is repeated periodically with a step corresponding to the width of the zone of influence of the successive feeds. In the example illustrated there are consequently three successive zones in which the shape B is repeated, covering in this manner the three successive feeds.

A movable cam 29 is shown which, when commanded, can be inserted or retracted from the track 28 in proximity to the region of passage between the zones A and B, and a thrust cam 30 which is also inserted or disengaged from the track 28 immediately after the cam 29 (it being naturally assumed that the track 28 is traversed from right to left of the figure).

The operation of the device will now be described.

For simplicity the operation of a single needle-jacklower jack assembly will be considered, starting from their entry into the zone of influence of the first feed (zone A).

Initially the needle 8, the jack 9 and lower jack 13 are located in the position shown in FIG. 3a.

When the jack 9 engages with the cam 26, it begins to rise so pushing the needle 8 which in its turn is guided by the cam 24. During this ascending movement of the jack 9 in its respective slot, the lower jack 13 is not involved in this movement because of the sliding engagement between the lower tooth 15 of the jack 9 and lower jack 13 and also between the upper tooth 16 of the lower jack l3 and appendix 14, jack 13 is consequently maintained in the initial position, with its own course 13a adhering to the bottom surface of the slot 7, and with the foot 20 disengaged from the ledge 21. In this first phase the needle 8 is brought to the level of the main thread guides 31 of the first feed.

Following the rotation of the needle cylinder, the jack 9 engages with the movable selection cam 27, which causes the jack 9 to slide further upwards. Because of this latter rise the needle 8 also rises, reaching the level of the supplementary thread guide 32 intended for example for feeding the reinforcing thread on the first feed. Because of the further rise of the jack 9, the lowerjack is also entrained upwards. In fact the tooth 15 of the jack 9 now hooks the tooth 16 of the lower jack 13 such that this latter, on rising, is forced because of the engagement of the foot 20 with the ledge 21 to move radially from the bottom of the slot 7, the tooth 15 forming a fulcrum point for said lower jack (FIG. 30). Because of this movement the butt 19 of the lowerjack 13, which up to that moment travelled past in front of the section a of the track 28, penetrates progressively into the track itself during its passage in front of section b of the track. At the end of the section b the butt 19 is completely engaged in the fixed track 28.

When the needle 8 reaches beyond the thread guide 32, the jack 9 redescends. It does not descend however together with the jack 9 the lower jack 13, because it is supposed that during this phase the movable cam 29 is disengaged from the track 28 while the butt 19 is guided by it (zone c).

In this condition it leaves the zone of influence of the feed A and it enters into the zone of influence of feed B. At the inlet to the zone B the situation is the following: the lower jack l3, engaged in the track 28, is in the position and at the level shown in FIG. 30. The jack 9 is however brought into the position shown in FIG. 3a, and hence rests with its own edge 18 against the head 16 of the lowerjack 13.

At the beginning of zone B, the jack 9, controlled by the cam 26, rises bringing the needle to the level of the thread guide 31. At the same time the lower jack l3, guided by'the track 28 over its section d, also rises.

At this point, the jack 9 has to rise further in order to bring the needle 8 to the level of the thread guide 32 of the feed B, in order to carry out the full fancy effect on the knitted fabric. This latter ascending course however is no longer controlled by a selector cam 27 of the type which works at feed A, and which does not exist at feed B. In this phase it is the lower jack 13 which, further rising guided by the section 2 of the track 28, pushes the jack 9 upwards, which in its turn pushes the needle 8.

Finally the needle 8 redescends, and together with it the jack 9 and lower jack 13 descend, this latter guided by the section f of the track 28. The assembly thus leaves the zone of influence of the feed B, and is ready to repeat the same cycle in a successive feed, without having to use selector cam 27 of the type present on the first feed.

It can happen that the repetition of the fancy motif of the knitting does not have to take place on all feeds successive to the first, but only on some of them. Further it may happen that the repetition of the fancy design by all feeds successive to the first is to be excluded. In order to obtain this effect, it is sufficient to disengage the butt 19 of the lower jack 13 from the track 28. In this case the jack 9 is subjected only to the movements caused by the cam 26, consequently the needle 8 does not arrive at the level of the thread guides 32 of the feeds successive to the first, and the knitting is not fancy worked at the successive feeds.

In order to disengage the butt 19 of the lower jack 13 from the track 28 before the butt enters the ascending ramp d and e, the retractable cam 29 is provided in the zone of the track 28. When the butt 19 is to be disengaged from said track, the cam 29 is inserted into it, guiding the descent of the butt 19 after the zone b. In this situation the lower jack 13 is brought into the lowest position of its travel (FIGS. 3a and 3b). However, as there exists the possibility that the butt 19, although having descended, has not disengaged from the track 28, a thrust cam 30 is provided (FIG. 4) which can be inserted into the track 28. In this case the butt 19, sliding on the profile of the cam 30, is removed from the track 28, so returning the lower jack 13 into the position shown in FIGS. 3a and 3b.

From this moment onwards the lower jack 13 can engage with the track 28 only if the jack 9 raises it by that short distance necessary to make the foot 20 engage with the ledge 21 (FIG. 3c).

Iclaim:

1. In a multi-feed circular knitting machine comprising a needle cylinder having a plurality of longitudinal slots, a plurality of needles and jacks slidable inside said slots and cam means for the selection and control of said needles and jacks, a device for carrying out fancy operations repeated at each feed, comprising a plurality of lower jacks arranged slidably inside said slots below said jacks in sliding engagement therewith, a cam member arranged around said needle cylinder adjacent said plurality of lower jacks, each of said lower jacks having a butt near its lower end and a foot opposite to said butt, control means for causing, the said ower acks to assume an operative position in WhlCh said butt projects from said slots in order to engage said cam member, wherein, according to the improvement, said control means comprise, in combination, actuation means for sliding engagement between said jacks and said lower jacks allowing said jacks and said lower jacks to move inside said slots for a travel portion without and before engaging each other, said travel portion being equal to the length of the vertical path travelled by the needles during the execution of the fancy work of the knitting, and an annular ledge arranged on said needle cylinder at the lower end thereof and having an outer peripheral surface with a diameter equal to that of said needle cylinder inside said slots, said foot of said lower jacks defining an inclined projecting surface cooperating with said outer peripheral surface when said lower jack is raised by said jack through said actuation means, thus causing said lower jack to project with its butt outwards of said slots for engaging said cam means and move accordingly.

2. A device as claimed in claim 1, wherein said actuation means for sliding engagement between said jacks and said lower jacks each comprise a lower appendix of said jacks extending substantially parallel to said slots and outwardly thereof and having a lower tooth portion projecting partially to the inside of said slots, said appendix defining with the jack a pushing edge inside said slots, and an upper tooth portion arranged on said lower jacks for engagement with said tooth portion of said jacks, said lower tooth portion forming a fulcrum point for said lower jack when it is raised by said jack and caused to project with its butt out of said slots through said foot engaging said annular ledge. 

1. In a multi-feed circular knitting machine comprising a needle cylinder having a plurality of longitudinal slots, a plurality of needles and jacks slidable inside said slots and cam means for the selection and control of said needles and jacks, a device for carrying out fancy operations repeated at each feed, comprising a plurality of lower jacks arranged slidably inside said slots below said jacks in sliding engagement therewith, a cam member arranged around said needle cylinder adjacent said plurality of lower jacks, each of said lower jacks having a butt near its lower end and a foot opposite to said butt, control means for causing the said lower jacks to assume an operative position in which said butt projects from said slots in order to engage said cam member, wherein, according to the improvement, said control means comprise, in combination, actuation means for sliding engagement between said jacks and said lower jacks allowing said jacks and said lower jacks to move inside said slots for a travel portion without and before engaging each other, said travel portion being equal to the length of the vertical path travelled by the needles during the execution of the fancy work of the knitting, and an annular ledge arranged on said needle cylinder at the lower end thereof and having an outer peripheral surface with a diameter equal to that of said needle cylinder inside said slots, said foot of said lower jacks defining an inclined projecting surface cooperating with said outer peripheral surface when said lower jack is raised by said jack through said actuation means, thus causing said lower jack to project with its butt outwards of said slots for engaging said cam means and move accordingly.
 2. A device as claimed in claim 1, wherein said actuation means for sliding engagement between said jacks and said lower jacks each comprise a lower appendix of said jacks extending substantially parallel to said slots and outwardly thereof and having a lower tooth portion projecting partially to the inside of said slots, said appendix defining with the jack a pushing edge inside said slots, and an upper tooth portion arranged on said lower jacks for engagement with said tooth portion of said jacks, said lower tooth portion forming a fulcrum point for said lower jack when it is raised by said jack and caused to project with its butt out of said slots through said foot engaging said annular ledge. 